995179a6c6
Add a test for this as well as it's annoying to point out in every code review. Fix all the import paths that are flagged by this new test. Fixes: #3634 Signed-off-by: Miek Gieben <miek@miek.nl>
112 lines
2.8 KiB
Go
112 lines
2.8 KiB
Go
// Package trace implements OpenTracing-based tracing
|
|
package trace
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
"sync"
|
|
"sync/atomic"
|
|
|
|
"github.com/coredns/coredns/plugin"
|
|
"github.com/coredns/coredns/plugin/metrics"
|
|
"github.com/coredns/coredns/plugin/pkg/dnstest"
|
|
"github.com/coredns/coredns/plugin/pkg/rcode"
|
|
_ "github.com/coredns/coredns/plugin/pkg/trace" // Plugin the trace package.
|
|
"github.com/coredns/coredns/request"
|
|
|
|
"github.com/miekg/dns"
|
|
ot "github.com/opentracing/opentracing-go"
|
|
zipkin "github.com/openzipkin-contrib/zipkin-go-opentracing"
|
|
"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/opentracer"
|
|
"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer"
|
|
)
|
|
|
|
const (
|
|
tagName = "coredns.io/name"
|
|
tagType = "coredns.io/type"
|
|
tagRcode = "coredns.io/rcode"
|
|
)
|
|
|
|
type trace struct {
|
|
Next plugin.Handler
|
|
Endpoint string
|
|
EndpointType string
|
|
tracer ot.Tracer
|
|
serviceEndpoint string
|
|
serviceName string
|
|
clientServer bool
|
|
every uint64
|
|
count uint64
|
|
Once sync.Once
|
|
}
|
|
|
|
func (t *trace) Tracer() ot.Tracer {
|
|
return t.tracer
|
|
}
|
|
|
|
// OnStartup sets up the tracer
|
|
func (t *trace) OnStartup() error {
|
|
var err error
|
|
t.Once.Do(func() {
|
|
switch t.EndpointType {
|
|
case "zipkin":
|
|
err = t.setupZipkin()
|
|
case "datadog":
|
|
tracer := opentracer.New(tracer.WithAgentAddr(t.Endpoint), tracer.WithServiceName(t.serviceName), tracer.WithDebugMode(true))
|
|
t.tracer = tracer
|
|
default:
|
|
err = fmt.Errorf("unknown endpoint type: %s", t.EndpointType)
|
|
}
|
|
})
|
|
return err
|
|
}
|
|
|
|
func (t *trace) setupZipkin() error {
|
|
|
|
collector, err := zipkin.NewHTTPCollector(t.Endpoint)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
recorder := zipkin.NewRecorder(collector, false, t.serviceEndpoint, t.serviceName)
|
|
t.tracer, err = zipkin.NewTracer(recorder, zipkin.ClientServerSameSpan(t.clientServer))
|
|
|
|
return err
|
|
}
|
|
|
|
// Name implements the Handler interface.
|
|
func (t *trace) Name() string { return "trace" }
|
|
|
|
// ServeDNS implements the plugin.Handle interface.
|
|
func (t *trace) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
|
|
trace := false
|
|
if t.every > 0 {
|
|
queryNr := atomic.AddUint64(&t.count, 1)
|
|
|
|
if queryNr%t.every == 0 {
|
|
trace = true
|
|
}
|
|
}
|
|
span := ot.SpanFromContext(ctx)
|
|
if !trace || span != nil {
|
|
return plugin.NextOrFailure(t.Name(), t.Next, ctx, w, r)
|
|
}
|
|
|
|
req := request.Request{W: w, Req: r}
|
|
span = t.Tracer().StartSpan(spanName(ctx, req))
|
|
defer span.Finish()
|
|
|
|
rw := dnstest.NewRecorder(w)
|
|
ctx = ot.ContextWithSpan(ctx, span)
|
|
status, err := plugin.NextOrFailure(t.Name(), t.Next, ctx, rw, r)
|
|
|
|
span.SetTag(tagName, req.Name())
|
|
span.SetTag(tagType, req.Type())
|
|
span.SetTag(tagRcode, rcode.ToString(rw.Rcode))
|
|
|
|
return status, err
|
|
}
|
|
|
|
func spanName(ctx context.Context, req request.Request) string {
|
|
return "servedns:" + metrics.WithServer(ctx) + " " + req.Name()
|
|
}
|